Fire retardant laminate

ABSTRACT

A fire retardant laminate includes a resin impregnated decorative layer, a fire barrier formed from a fiber reinforced veil and a layer of fiberboard. A method of making a fire retardant laminate is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 11/108,340 filed Apr. 18, 2005.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

This invention relates generally to fire retardant laminates such as utilized for flooring.

BACKGROUND OF THE INVENTION

Laminated flooring formed from boards having a wood basis such as chipboard or fiberboard are known in the aft. The present invention relates to a novel laminate characterized by improved fire and impact resistance.

SUMMARY OF THE INVENTION

The fire retardant laminate of the present invention comprises a resin impregnated decorative layer, a fire barrier formed from a fiber reinforced veil and a layer of fiberboard. The fiber reinforced veil includes fibers selected from a group consisting of glass fibers, basalt fibers, metal fibers, inorganic fibers, silica fibers, carbide fibers, nitride fibers, carbon fibers and mixtures thereof. Glass fibers utilized for the fiber reinforced veil may be selected from a group of materials consisting of boron-free glass, E-glass, ECR-glass, C-glass, AR-glass, S2-glass and mixtures thereof.

The fiber reinforced veil also includes a binder comprising a B-stageable resin. Suitable binders include but are not limited to self-crosslinkable polyacrylates, polyamide-amine epichlorohydrin resin (PAE), polyvinyl alcohol, acrylates, styrene acrylates, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, epoxy resin, unsaturated polyesters, crosslinkable acrylic resin, polyurethane resin and mixtures thereof. The fiber reinforced veil also includes a filler selected from a group consisting of aluminum trihydrate, magnesium hydroxide, melamine cyanurate, halogenated additive, antimony trioxide, metal hydroxide, metal carbonate, titanium dioxide, calcined clay, barium sulfate, magnesium sulfate, aluminum sulfate, zinc oxide, kaolin clay, chlorite, diatomite, felspar, mica, nepheline syenite, pyrophyllite, silica, talc, wollastonite, montmorillonite, hectorite, saponite, calcium carbonate, magnesium carbonate, aluminum oxide, iron oxide, glass microbeads, ethylenediaminephosphate, guanidinephosphates, melamine borate, melamine (mono, pyro, poly) phosphate, ammonium (mono, pyro, poly) phosphate, dicyandiamide condensates, general intumescent systems (systems which foam during fire and therefore generate in situ an insulating layer) and mixtures thereof.

In one possible embodiment the fiber reinforced veil is nonwoven. Following resin impregnation, the fiber reinforced veil includes between about 5 to about 95 weight percent reinforcement fibers, about 5 to about 75 weight percent binder and about 0 to about 80 weight percent filler. Following impregnation and prior to pressing, the fiber reinforced veil has a weight per unit area of between about 20 and about 500 g/m².

The layer of fiberboard in the laminate may be generally described as a wood-based panel. The fiberboard may be constructed from a material selected from the group consisting of high density fiberboard, medium density fiberboard, oriented strand board, chipboard and mixtures thereof. In addition the laminate may include a layer of resin impregnated overlay paper overlying the resin impregnated decorative paper and/or a resin impregnated backing layer underlying the layer of fiberboard. Both the resin impregnated decorative layer and the resin impregnated backing layer may be made from a decorative paper of a type known in the art.

In accordance with an additional aspect of the present invention a method is provided for making a fire retardant laminate. The method comprises pressing a resin impregnated overlay layer, a resin impregnated decorative layer, a fire barrier formed from a fiber reinforced veil, a layer of fiberboard and a resin impregnated backing layer together at a pressure of between about 1050 N/m² and about 5250 N/m² while simultaneously heating to a temperature of between about 150 to about 225 degrees C. for a time period of between about 10 to about 50 seconds. That method may be further described as including a step of providing a binder in the fiber reinforced veil selected from a group consisting of polyvinyl alcohol, acrylates, styrene acrylates, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, epoxy resin, unsaturated polyesters, crosslinkable acrylic resin, polyurethane resin, polyamide-amine epichlorohydrin resin and mixtures thereof.

Still further the method may include the step of providing a filler in the fiber reinforced veil selected from a group consisting of aluminum trihydrate, magnesium hydroxide, melamine cyanurate, halogenated additive, antimony trioxide, metal hydroxide, metal carbonate, titanium dioxide, calcined clay, barium sulfate, magnesium sulfate, aluminum sulfate, zinc oxide, kaolin clay, chlorite, diatomite, felspar, mica, nepheline syenite, pyrophyllite, silica, talc, wollastonite, montmorillonite, hectorite, saponite, calcium carbonate, magnesium carbonate, aluminum oxide, iron oxide, glass microbeads, ethylenediaminephosphate, guanidinephosphates, melamine borate, melamine (mono, pyro, poly) phosphate, ammonium (mono, pyro, poly) phosphate, dicyandiamide condensates, general intumescent systems and mixtures thereof.

As mentioned, the laminate may be used in a laminate flooring application wherein the laminate is formed from boards having a wood basis such as chipboard, fiberboard including high and medium density fiberboard, and oriented strand board. Additional applications for the laminate include, but are not limited to, wall linings, ceilings, interior shop fittings, and decoration panels such as those found in ships, trains, and buildings.

In the following description there is shown and described one possible embodiment of the invention simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing incorporated in and forming a part of this specification, illustrates several aspects of the present invention, and together with the description serves to explain certain principles of the invention. In the drawing:

FIG. 1 is a side elevational view of one possible embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIG. 1 illustrating one possible embodiment of the laminate 10 of the present invention. As illustrated the laminate 10 includes a resin impregnated overlay paper 12 overlying a resin impregnated decorative layer 14. The decorative layer 14 overlies a first fire barrier formed from a fiber reinforced veil 16. The veil 16 overlies a layer of fiberboard 18. Finally, a backing layer 20 underlies the fiberboard 18. The laminate 10 may also include a second fire barrier, formed from a fiber reinforced veil 22, between the fiberboard 18 and the backing layer 20. This second veil 22 further enhances the fire retardant properties of the laminate 10 and insures that heat is transferred at about the same rate from the top or the bottom.

More specifically describing the invention, the fiber reinforced veil 16 may include fibers selected from a group consisting of glass fibers, basalt fibers, metal fibers, inorganic fibers, silica fibers, carbide fibers, nitride fibers, carbon fibers and mixtures thereof. Where glass fibers are utilized in the fiber reinforced veil, they may, for example, be selected from a group of fibers including boron-free glass, E-glass, ECR-glass, C-glass, AR-glass, S2-glass and mixtures thereof. Advantex® glass fibers, commercially available from Owens Corning (Toledo, Ohio), may be used.

The fiber reinforced veils 16 and 22 following resin impregnation includes between about 5 to about 95 weight percent reinforcement fibers, about 5 to about 75 weight percent resin/binder and 0 to about 80 weight percent filler. The binder utilized may be a B-stageable resin which may be reactivated during the pressing step to reach its final properties. The binder may be selected from a group of resins consisting of polyvinyl alcohol, acrylates, styrene acrylates, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, epoxy resin, unsaturated polyesters, crosslinkable acrylic resin, polyurethane resin, polyamide-amine epichlorohydrin resin and mixtures thereof. The filler utilized in the fiber reinforced veil 16 may be selected from a group consisting of aluminum trihydrate, magnesium hydroxide, melamine cyanurate, halogenated additive, antimony trioxide, metal hydroxide, metal carbonate, titanium dioxide, calcined clay, barium sulfate, magnesium sulfate, aluminum sulfate, zinc oxide, kaolin clay, chlorite, diatomite, felspar, mica, nepheline syenite, pyrophyllite, silica, talc, wollastonite, montmorillonite, hectorite, saponite, calcium carbonate, magnesium carbonate, aluminum oxide, iron oxide, glass microbeads, ethylenediaminephosphate, guanidinephosphates, melamine borate, melamine (mono, pyro, poly) phosphate, ammonium (mono, pyro, poly) phosphate, dicyandiamide condensates, general intumescent systems (systems which foam during fire and therefore generate in situ an insulating layer) and mixtures thereof. Advantageously, the fire barrier formed from the fiber reinforced veil 16 imparts improved fire retarding and impact characteristics to the laminate above and beyond those achieved with wood based laminates of the prior art not incorporating a fire barrier of fiber reinforced veil.

The fiber reinforced veils 16 and 22 are typically constructed from nonwoven glass fibers or mixed fibers. The veils 16, 22 may include directionally oriented fibers if desired. Both continuous and chopped fibers may be utilized. The continuous fibers typically have a diameter of between about 3 and about 30. The chopped fibers typically have a length of between about 2 and about 100 mm and a diameter of between about 3 and about 30 μm. The fiber reinforced veil 16 following impregnation and prior to pressing typically has a weight per unit area of between about 20 and about 500 g/m².

The fiberboard 18 utilized in the present laminate is a wood based panel. The fiberboard 18 may, for example, be made from materials including high density fiberboard, medium density fiberboard, oriented strand board, chipboard and mixtures thereof.

The decorative layer 14 and backing layer 20 may be made from decorative paper as is known in the art. The overlay paper 12 may be made from cellulose as is also known in the art. The overlay paper 12, the decorative layer 14 and the backing layer 20 may all be impregnated with the same resin/binder as the fiber reinforced veil 16.

The laminate 10 is made by pressing the resin impregnated overlay layer 12, the resin impregnated decorative layer 14, the first fire barrier formed from the resin impregnated, fiber reinforced veil 16, the layer of fiberboard 18, the second fire barrier formed from the resin impregnated fiber reinforced veil 22 (if present) and the resin impregnated backing layer 20 together at a pressure of between about 1050 N/M² while simultaneously heating to a temperature of between about 225 degrees C. for a time period of between about 10 to about 50 seconds. Such processing may be completed in-line utilizing equipment that is presently available in the commercial marketplace.

EXAMPLES

Table 1 shows fifteen samples of glass veil, prior to impregnation with additional binder and a flame retarder. All samples contain a poly(vinyl alcohol) (PVA) binder. The glass fibers in the veil include Advantex® glass fibers manufactured by Owens Corning, Toledo, Ohio, USA. TABLE 1 glass Ni weight binder SAMPLE FIBER TYPE g/m2 perc % 1 Advantex; 47 15 11 um-6 mm 2 Advantex; 46 15 11 um-6 mm 3 Advantex; 47 15 11 um-6 mm 4 Advantex; 47 15 11 um-6 mm 5 Advantex; 46 15 11 um-6 mm 6 Advantex; 46 15 11 um-6 mm 7 Advantex; 47 15 11 um-6 mm 8 Advantex/silica 33 10 (85:15) 9 Advantex/silica 54 10 (85:15) 10 Advantex/silica 76 10 (85:15) 11 Advantex/silica 48 10 (85:15) 12 Advantex/silica 47 10 (85:15) 13 silica 100% 81 12 14 Advantex; 35 15 11 um-6 mm 15 Advantex; 35 15 11 um-6 mm

Table 2 shows samples 1-15 after they have been impregnated with additional binder and flame retardant. The “Add on” column shows the amount of fire retarder/filler per m2 impregnated into each sample. TABLE 2 GLASS VEIL IMPREGNATION End Sample Binder Flame Add on weight No. type retarder (g/M2) (g/M2) 1 PVA melamine 26 73 phosphate 2 PVA Melamine 25 71 pyrophosphate 3 PVA Melamine 26 73 cyanurate 4 PVA Ammonium 25 72 polyphosphate 5 chlorine- Aluminum 25 71 acrylate trihydrate 6 chlorine- ATH + APP 24 70 acrylate 7 PVA none 0 47 8 none none 0 33 9 none none 0 54 10 none none 0 76 11 PVA APP 23 71 12 PVA Melamine 24 71 polyphosphate 13 none none 0 81 14 PVA ATH 7 42 15 PVA intumescent 7 42 formulation

Table 3 shows the fire properties of samples 1-15 when each of the samples were exposed to flame. Samples 1-15 were lit above a Bunsen burner where the flame temperature reached about 950° C. Distance to the flame was fixed, about 20 mm, for all the samples to ensure that the samples were exposed to the same temperature. Samples were observed for smoke development then the samples were removed from the flame and observed for self-extinguishing behavior. TABLE 3 FIRE PROPERTIES Smoke Self- Burn-through Sample No. Development* Extinguishing** times (s) 1 + +++ 40 2 + +++ 20 3 ++ +++ 3 4 + +++ 159 5 + ++ 3 6 + +++ 130 7 − + 1 8 −− +++ 600 9 −− +++ 170 10 −− +++ 300 11 + +++ 250 12 + +++ 26 13 −− +++ >600 14 + +++ 1 15 ++ +++ 250 *Smoke development: −−: no smoke development −: hardly any smoke development +: moderate smoke development ++: significant smoke development **Self-extinguishing behavior +: poor self-extinguishing properties ++: moderate self-extinguishing properties +++: significant self-extinguishing properties

The samples were then placed at a fixed distance, about 10 mm, above a Bunsen burner (Flame temperature at about 950° C.) and the time (in seconds) was recorded when the flame burned through the veil samples.

Flooring Laminate Examples

Specimens 7 and 14 were evaluated as an effective fire barrier in a laminate flooring panel. An unmodified flooring laminate was taken as a reference. The laminate flooring panels were evaluated on impact resistance and fire resistance.

Method of Making the Laminate Flooring Panel:

Specimens 7 and 14 were impregnated with melamine resin to ensure a good bonding with the decorative paper and with the fiber board. Specimens 7 and 14 were impregnated to final weights of approximately 150 g/m2.

The melamine-impregnated specimens 7 and 14 were pressed (function as a fire barrier between the decorative paper and the fiber board) onto the 8 mm high density fiber board (pressing conditions: 180° C.; 40 kg/cm2; 20 s) to produce the laminate flooring panel. The final laminate flooring panel was subjected to two critical tests; impact resistance and fire resistance and tested with a reference laminate flooring panel, see Table 4. TABLE 4 Code C: Code A: Code B: Specimen 14 Unmodified Specimen 7 fire barrier standard fire barrier laminate laminate laminate flooring Norm flooring panel flooring panel panel Small ball EN 438 <15 16.82 18.84 impact (N) Large ball EN 438 <1600 >1600 >1600 impact (mm) Fire NF P 92- M3 M2 M2 resistance 501 Impact class IC1 or IC 2 IC 3 IC 3 (see FIG. 2)

As shown in Table 4, laminate flooring panels A, B and C were tested using the small and large ball impact tests described below. In the small ball impact test, the panels with their decorative surfaces were subjected to the impact of a 5 mm steel ball mounted at one end of a spring-loaded bolt. The minimum spring force (N) needed to cause visible damage was used to measure resistance to impact. In the large ball impact test, the laminate flooring panels A, B and C were covered with a sheet of carbon paper and subjected to the impact of a large steel ball (324 g; diameter of 42.8 mm) which was allowed to fall from a known height. In the large ball test, the height is increased in 50 mm intervals until the ball creates an impact imprint larger than 10 mm. This height determines the large ball impact resistance in mm. Impact resistance is expressed as the maximum drop height (mm) which can be achieved without incurring visible surface cracking or producing an imprint greater than a 10 mm diameter.

Fire Resistance

The Epiradiateur test (NF P 92-501) is the national fire test for France and is mandatory for many building and construction materials.

The size of the specimens (7 and 14) tested was 300 mm×400 mm×max 120 mm and the specimens were positioned at an incline of 45° on an 8 mm fixed, self-supporting frame. The specimens were ignited, from above and below, using an electrical radiator (inclined at 45°) at 500 W. Two butane pilot flames were used to ignite the fiber board panels above and below the specimen for 20 minutes.

FIG. 2 shows the impact classification ratings using both the small ball impact test and the large ball impact test.

The foregoing description of a preferred embodiment of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, the second fire barrier and the backing layer could be combined into a single layer if desired.

The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims and their fair and broad interpretation in any way. 

1. A fire retardant laminate, comprising: a resin impregnated decorative layer; a first fire barrier formed from a fiber reinforced veil; and a layer of fiberboard.
 2. The laminate of claim 1, wherein said first fiber reinforced veil includes fibers selected from a group consisting of glass fibers, basalt fibers, metal fibers, inorganic fibers, silica fibers, carbide fibers, nitride fibers, carbon fibers and mixtures thereof.
 3. The laminate of claim 1, wherein said first fiber reinforced veil includes glass fibers selected from a group of fibers including boron-free glass, E-glass, ECR-glass, C-glass, AR-glass, S2-glass and mixtures thereof.
 4. The laminate of claim 1, wherein said first fiber reinforced veil includes a binder comprising a B-stageable resin.
 5. The laminate of claim 1, wherein said first fiber reinforced veil includes a binder selected from a group consisting of polyvinyl alcohol, acrylates, styrene acrylates, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, epoxy resin, unsaturated polyesters, crosslinkable acrylic resin, polyurethane resin, polyamide-amine epichlorohydrin resin and mixtures thereof.
 6. The laminate of claim 1, wherein said first fiber reinforced veil includes a filler selected from a group consisting of aluminum trihydrate, magnesium hydroxide, melamine cyanurate, halogenated additive, antimony trioxide, metal hydroxide, metal carbonate, titanium dioxide, calcined clay, barium sulfate, magnesium sulfate, aluminum sulfate, zinc oxide, kaolin clay, chlorite, diatomite, felspar, mica, nepheline syenite, pyrophyllite, silica, talc, wollastonite, montmorillonite, hectorite, saponite, calcium carbonate, magnesium carbonate, aluminum oxide, iron oxide, glass microbeads, ethylenediaminephosphate, guanidinephosphates, melamine borate, melamine (mono, pyro, poly) phosphate, ammonium (mono, pyro, poly) phosphate, dicyandiamide condensates, general intumescent systems and mixtures thereof.
 7. The laminate of claim 1, wherein said first fiber reinforced veil is nonwoven.
 8. The laminate of claim 1, further including a second fire barrier formed from a fiber reinforced veil, said layer of fiberboard being sandwiched between said first and second fire barriers.
 9. The laminate of claim 8, wherein said fiber reinforced veils of said first and second fire barriers following resin impregnation include between about 5 to about 95 weight percent reinforcement fibers, about 5 to about 75 weight percent binder and 0 to about 80 weight percent filler.
 10. The laminate of claim 9, wherein said fiber reinforced veils of said first and second fire barriers include a resin binder selected from a group consisting of polyvinyl alcohol, acrylates, styrene acrylates, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, epoxy resin, unsaturated polyesters, crosslinkable acrylic resin, polyurethane resin, polyamide-amine epichlorohydrin resin and mixtures thereof.
 11. The laminate of claim 10, wherein said fiber reinforced veils of said first and second fire barriers include a filler selected from a group consisting of aluminum trihydrate, magnesium hydroxide, melamine cyanurate, halogenated additive, antimony trioxide, metal hydroxide, metal carbonate, titanium dioxide, calcined clay, barium sulfate, magnesium sulfate, aluminum sulfate, zinc oxide, kaolin clay, chlorite, diatomite, felspar, mica, nepheline syenite, pyrophyllite, silica, talc, wollastonite, montmorillonite, hectorite, saponite, calcium carbonate, magnesium carbonate, aluminum oxide, iron oxide, glass microbeads, ethylenediaminephosphate, guanidinephosphates, melamine borate, melamine (mono, pyro, poly) phosphate, ammonium (mono, pyro, poly) phosphate, dicyandiamide condensates, general intumescent systems and mixtures thereof.
 12. The laminate of claim 9 wherein said fiber reinforced veils of said first and second fire barriers following impregnation and prior to pressing have a weight per unit area of between about 20 and about 500 g/m².
 13. The laminate of claim 1, wherein said layer of fiberboard is a wood-based panel.
 14. The laminate of claim 1, wherein said layer of fiberboard is selected from a group of materials consisting of high density fiberboard, medium density fiberboard, oriented strand board, chipboard and mixtures thereof.
 15. The laminate of claim 1, further including a layer of resin impregnated overlay paper overlying said resin impregnated decorative layer and a resin impregnated backing layer underlying said layer of fiberboard.
 16. The laminate of claim 15, further including a resin impregnated backing layer underlying said layer of fiberboard.
 17. The laminate of claim 16, wherein said resin impregnated decorative layer and said resin impregnated backing layer are both made from decorative paper.
 18. The laminate of claim 1, wherein said laminate is a flooring laminate.
 19. The laminate of claim 1, wherein said laminate is classified in impact class 3 (IC3).
 20. A method of making a fire retardant laminate, comprising: pressing a resin impregnated overlay layer, a resin impregnated decorative layer, a fire barrier formed from a resin impregnated, fiber reinforced veil, a layer of fiberboard and a resin impregnated backing layer together at a pressure of between about 1050 N/m² and about 5250 N/m² while simultaneously heating to a temperature of between about 150 to about 225 degrees C. for a time period of between about 10 to about 50 seconds.
 21. The method of claim 20, further including a step of providing a resin binder in said fiber reinforced veil selected from a group consisting of polyvinyl alcohol, acrylates, styrene acrylates, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, epoxy resin, unsaturated polyesters, crosslinkable acrylic resin, polyurethane resin, polyamide-amine epichlorohydrin resin and mixtures thereof.
 22. The method of claim 21, further including a step of providing a filler in said fiber reinforced veil selected from a group consisting of aluminum trihydrate, magnesium hydroxide, melamine cyanurate, halogenated additive, antimony trioxide, metal hydroxide, metal carbonate, titanium dioxide, calcined clay, barium sulfate, magnesium sulfate, aluminum sulfate, zinc oxide, kaolin clay, chlorite, diatomite, felspar, mica, nepheline syenite, pyrophyllite, silica, talc, wollastonite, montmorillonite, hectorite, saponite, calcium carbonate, magnesium carbonate, aluminum oxide, iron oxide, glass microbeads and mixtures thereof.
 23. The method of claim 20, including providing a second fire barrier formed from a resin impregnated, fiber reinforced veil between said layer of fiberboard and said resin impregnated backing layer. 